An inflammatory biomarker as a differential predictor of outcome of depression treatment with escitalopram and nortriptyline

Association of C-reactive protein and metabolic risk with cognitive effects of lurasidone in patients with schizophrenia

BACKGROUND

Accumulating evidence has implicated insulin resistance and inflammation in the pathophysiology of cognitive impairments associated with neuropsychiatric disorders. This post-hoc analysis based on a placebo-controlled trial investigated the effect of inflammation (indexed by CRP) and metabolic risk factors on cognitive performance in patients with schizophrenia treated with lurasidone.

METHODS

Acutely exacerbated patients with schizophrenia were randomized to lurasidone (80 or 160 mg/day), quetiapine XR 600 mg/day, or placebo. A wide range CRP test and a cognitive assessment using the CogState computerized battery were performed at baseline and week 6 study endpoint. Associations between log-transformed CRP, high density lipoprotein (HDL), homeostatic model assessment of insulin resistance (HOMA-IR) and treatment response were evaluated.

RESULTS

CRP combined with HDL, triglyceride-to-HDL (TG/HDL) ratio, or HOMA-IR at study baseline were significant moderators of the improvement in cognitive performance associated with lurasidone 160 mg/day (vs. placebo) treatment (p < .05). Greater placebo-corrected treatment effect size on the CogState composite score was observed for patients in the lurasidone 160 mg/day treatment group who had either low CRP and high HDL (d = 0.43), or low CRP and low HOMA-IR (d = 0.46). Interactive relationships between CRP, HDL, TG/HDL, HOMA-IR and the antipsychotic efficacy of lurasidone or quetiapine XR were not significant. There were no significant associations between antipsychotic treatment and changes in CRP level at study endpoint.

CONCLUSIONS

Findings of this post-hoc analysis based on a placebo-controlled trial in patients with schizophrenia suggest that baseline CRP level combined with measures of metabolic risk significantly moderated the improvement in cognitive performance associated with lurasidone 160 mg/day (vs. placebo) treatment. Our findings underscore the importance of maintaining a low metabolic risk profile in patients with schizophrenia.

A Longitudinal Analysis of Inflammation and Depression in Patients With Metastatic Lung Cancer: Associations With Survival

BACKGROUND

Depression and inflammation are concomitantly elevated in patients with lung cancer and may have collective survival implications. However, the longitudinal relationship between depression and inflammation in patients with metastatic lung cancer is not fully appreciated. We hypothesized that longitudinal changes in inflammation and depression would be concordant; that longitudinally elevated inflammation would lead to greater depression over time; and that depression with inflammation would be more persistent than depression without inflammation.

METHODS

Patients with metastatic lung cancer (n = 68) were assessed for clinically significant depression (Hospital Anxiety and Depression Scale ≥ 8) and inflammation (C-Reactive Protein ≥ 1 mg/L) along with demographic variables. Survival estimations were made using Cox Proportional Hazard Model and Kaplan-Meier plot analyses.

RESULTS

At baseline (T1), 15% had depression and 35% had increased inflammation followed by 18% with depression and 38% with increased inflammation 4.7 months later (T2). The odds ratio of depression in the presence of clinically significant inflammation was 4.8 at T1 and 5.3 at T2. Between time points, inflammation difference correlated with depression difference (r = -.26, p = .03). Significant depression at both time points was associated with a 4 fold risk of inferior survival while significant inflammation at any time point was associated with >3 fold risk of inferior survival.

CONCLUSIONS

Depression and inflammation track together over time and have variable implications on survival. Persistent depression is particularly detrimental but incidental inflammation is more sensitive to predicting poor survival. These findings have implications for treating depression early in the lung cancer trajectory.

Depression Heterogeneity and Its Biological Underpinnings: Toward Immunometabolic Depression

Epidemiological evidence indicates the presence of dysregulated homeostatic biological pathways in depressed patients, such as increased inflammation and disrupted energy-regulating neuroendocrine signaling (e.g., leptin, insulin). Alterations in these biological pathways may explain the considerable comorbidity between depression and cardiometabolic conditions (e.g., obesity, metabolic syndrome, diabetes) and represent a promising target for intervention. This review describes how immunometabolic dysregulations vary as a function of depression heterogeneity by illustrating that such biological dysregulations map more consistently to atypical behavioral symptoms reflecting altered energy intake/expenditure balance (hyperphagia, weight gain, hypersomnia, fatigue, and leaden paralysis) and may moderate the antidepressant effects of standard or novel (e.g., anti-inflammatory) therapeutic approaches. These lines of evidence are integrated in a conceptual model of immunometabolic depression emerging from the clustering of immunometabolic biological dysregulations and specific behavioral symptoms. The review finally elicits questions to be answered by future research and describes how the immunometabolic depression dimension could be used to dissect the heterogeneity of depression and potentially to match subgroups of patients to specific treatments with higher likelihood of clinical success.

Getting under the skin: Does biology help predict chronicity of depression?

BACKGROUND

Depressed patients are at risk of an unfavourable course including chronic episodes. Various psychiatric characteristics have shown to be predictive of depression's course trajectory, but whether indicators of somatic health further contribute to course prediction remains unclear. This study aimed to identify somatic health indicators (i.e. biomarkers, health status and lifestyle) that predict 2-year chronicity above and beyond an extensive list of sociodemographic and psychiatric characteristics.

METHODS

Data are from patients with current depression at baseline (n = 903) and available 2-year follow-up participating in a longitudinal cohort study. Baseline demographic, psychiatric and somatic health indicators were associated with 2-year course trajectories, classified as non-chronic versus chronic RESULTS: At 2-year follow up, 40% of the patients showed a chronic course. Of the twenty tested somatic health indicators, short sleep and high interleukin-6 improved the regression model predicting chronicity with a significant, but modest, effect (ROC = 0.78; p = 0.03).

LIMITATIONS

Due to the observational design we did not have the ability to reliably consider the impact of psychiatric treatment. More elaborate information on somatic health such as dietary patterns would strengthen the study.

CONCLUSIONS

This study showed that short sleep duration and high interleukin-6 contributed significantly to the regression model as independent predictors, suggestive of clinical implications for patients with sleep disturbances and elevated inflammation levels. Other somatic health indicators did not add to the model. Overall, somatic health indicators showed modest additive value for predicting chronic course above and beyond sociodemographic and psychiatric indicators.

Using prefrontal and midline right frontal EEG-derived theta cordance and depressive symptoms to predict the differential response or remission to antidepressant treatment in major depressive disorder

There is a growing need for optimizing treatment selection and response prediction in individuals with major depressive disorder (MDD). Prior investigations have shown that changes in electroencephalographic (EEG)-based measures precede symptom improvement and could serve as biomarkers of treatment outcome. One such method is cordance, a computation of regional brain activity based on a combination of absolute and relative resting EEG activity. Specifically, early reduction in prefrontal (PF) and midline right frontal (MRF) theta (4-8Hz) cordance has been shown to predict response to various antidepressants, though replication is required. Thus, this study examined early changes (baseline to week 1) in PF and MRF cordance in 47 MDD patients undergoing antidepressant treatment. Early changes in cordance and in Montgomery Åsberg Depression Rating Scale (MADRS) scores were assessed alone, and in combination, to predict eventual (by week 12) treatment response and remission. Models combining early changes in theta cordance (PF and MRF) and depressive symptoms were most predictive of response to treatment at week 12; remission models (cordance, MADRS, and their combination) were weaker, though provided modest prediction values. These results suggest that antidepressant response may be optimally predicted by combining both EEG and symptom-based measures after one week of treatment.

Higher levels of plasma inflammation biomarkers are associated with depressed mood and quality of life in aging, virally suppressed men, but not women, with HIV

Background and objectives

People with HIV (PWH) often suffer from depressive symptoms which have a deleterious impact on numerous domains including antiretroviral adherence and quality of life. In the general population, a treatment-resistant phenotype of depression is associated with systemic inflammation, which is of considerable importance as it responds favorably to anti-inflammatory medications. Aging PWH experience increasing inflammation. We sought to evaluate the impact of chronic inflammation in aging PWH on depressed mood.

Methods

PWH were recruited at 6 U.S. academic medical centers. Depressed mood was assessed using the Beck Depression Inventory (BDI)-II. Inflammatory biomarkers measured at the 12-year follow-up visit in blood plasma using immunoassays were neopterin, sTNFRII, d-dimer, IL-6, CRP, MCP-1, sCD14 and sCD40L. Factor analyses with oblique Equamax rotation were employed to reduce the dimensionality of the biomarkers.

Results

Participants were 78 PWH, 14 (17.9%) women, 40 (51.3%) non-White, mean age 55.3 (±SD 8.29), with a nadir and current CD4 of 134 (IQR 36, 204) and 567 (316, 797), respectively. 80.5% were virally suppressed. A factor analysis of the eight inflammatory biomarkers in plasma at the 12-year follow-up visit yielded 3 Factors, with Factor 1 loading on neopterin and sTNFRII, Factor 2 loading on d-dimer, IL-6 and CRP, and Factor 3 loading on sCD40L (MCP-1 and sCD14 did not appear in any of the factors). Univariate regressions of each factor vs BDI-II scores yielded significance only for Factor 2 (r ​= ​0.295; p ​= ​0.0083 (Bonferroni-adjusted p ​= ​0.0261). Of the Factor 2 component biomarkers, BDI-II scores correlated significantly with d-dimer and IL-6, but not CRP. Women had worse BDI-II scores (p ​= ​0.0127). In a logistic regression with sex and Factor 2, both variables were significant (sex p ​= ​0.0246, Factor 2 p ​= ​0.0168). The relationship between Factor 2 and BDI was significant for men (r ​= ​0.348 [95% CI 0.111, 0.547]; p ​= ​0.0049), but not women (r ​= ​0.0580 95% CI -0.488, 0.571]; p ​= ​0.844). Viral suppression was not significant in the multivariate model.

Conclusions

Some PWH with depressed mood have elevated markers of inflammation in blood. Men showed this relationship, while women did not. Together with previous findings that an inflammatory depression phenotype responds to treatment with anti-inflammatory medications, our findings suggest that treatment with anti-inflammatory medications might benefit at least a subset of depressed PWH who have a high inflammatory biomarker profile, as well as poor response to antidepressant medications alone, and that the pathophysiology of depression in men and women with HIV may differ.

Positive and negative valence systems in major depression have distinct clinical features, response to antidepressants, and relationships with immunomarkers

BACKGROUND

Heterogeneity in major depressive disorder (MDD) is well recognized but not well understood. Core depressive features are reward and emotional symptoms, which reflect dysfunctions in the positive valence (PV) and negative valence (NV) systems, respectively. This study assessed whether PV and NV systems (based on selected symptoms) were associated with different clinical features, antidepressant response, and levels of immunomarkers in adults with MDD.

METHODS

These analyses used data from combining medications to enhance depression outcomes study (N = 665; n = 166 for immunomarkers). PV and NV symptom scores were extracted from the clinician-rated 30-item Inventory of Depressive Symptomatology. Correlational analyses were conducted.

RESULTS

PV and NV symptom scores were substantially associated with different clinical features. PV symptoms (impaired motivation, impaired energy, and anhedonia) were independently associated with female gender (p < .001), older age (p = .012), and higher cognitive and physical impairment (p < .001) according to the 7-item Cognitive and Physical Functioning Questionnaire. Conversely, NV symptoms (anxiety and interpersonal sensitivity) were independently associated with younger age (p = .013), more anxious comorbidities (p = .001 for generalized anxiety disorder and p = .002 for social phobia) and other commonly associated noncriterion symptoms (p < .001). Overall, PV symptoms were more responsive to antidepressants than NV symptoms (p < .0001; Cohen's d = .455). A PV symptom score was positively correlated with the concentration of three proinflammatory and one anti-inflammatory factor. In contrast, an NV symptom score was negatively associated with only one proinflammatory immunomarker.

CONCLUSIONS

PV and NV system functions appear to be reflected in selected clinical symptoms that differentially relate to other clinical features, treatment outcomes, and immunological function.

Basal and LPS-stimulated inflammatory markers and the course of individual symptoms of depression

Multiple studies show an association between inflammatory markers and major depressive disorder (MDD). People with chronic low-grade inflammation may be at an increased risk of MDD, often in the form of sickness behaviors. We hypothesized that inflammation is predictive of the severity and the course of a subset of MDD symptoms, especially symptoms that overlap with sickness behavior, such as anhedonia, anorexia, low concentration, low energy, loss of libido, psychomotor slowness, irritability, and malaise. We tested the association between basal and lipopolysaccharide (LPS)-induced inflammatory markers with individual MDD symptoms (measured using the Inventory of Depressive Symptomatology Self-Report) over a period of up to 9 years using multivariate-adjusted mixed models in 1147-2872 Netherlands Study of Depression and Anxiety (NESDA) participants. At baseline, participants were on average 42.2 years old, 66.5% were women and 53.9% had a current mood or anxiety disorder. We found that basal and LPS-stimulated inflammatory markers were more strongly associated with sickness behavior symptoms at up to 9-year follow-up compared with non-sickness behavior symptoms of depression. However, we also found significant associations with some symptoms that are not typical of sickness behavior (e.g., sympathetic arousal among others). Inflammation was not related to depression as a unified syndrome but rather to the presence and the course of specific MDD symptoms, of which the majority were related to sickness behavior. Anti-inflammatory strategies should be tested in the subgroup of MDD patients who report depressive symptoms related to sickness behavior.

The relationship between plasma serotonin and kynurenine pathway metabolite levels and the treatment response to escitalopram and desvenlafaxine

INTRODUCTION

The response of patients with major depressive disorders (MDD) to antidepressant treatments have been shown to be affected by multiple factors, including disease severity and inflammation. Increasing evidence indicates that the kynurenine metabolic pathway is activated by inflammation in MDD patients and plays a role in the pathophysiology of depression. Antidepressant treatments have been reported to affect kynurenine pathway metabolite levels as well. This study investigates differential associations between the antidepressant treatment outcome to escitalopram versus desvenlafaxine with the pre-treatment and post-treatment-changes in serotonin and kynurenine pathway metabolite levels.

METHODS

The levels of serotonin and of kynurenine pathway metabolites were measured in plasma using liquid chromatography-mass spectrometry (LC-MS) in 161 currently depressed patients with MDD at baseline and after 8 weeks of treatment with either escitalopram or desvenlafaxine. Treatment response was defined conventionally by a reduction of at least 50% in the Hamilton Depression Rating Scale 21 item (HAMD-21) total score from baseline; remission was defined by reaching a post-treatment HAMD-21 score ≤7.

RESULTS

Response to escitalopram treatment was associated with higher baseline serotonin levels (p = 0.022), lower baseline kynurenine (Kyn)/tryptophan (Trp) ratio (p = 0.008) and lower baseline quinolinic acid (QuinA)/tryptophan (Trp) ratio (p = 0.047), suggesting a lower inflammation state. Greater improvement in depression symptoms as measured by percent change of HAMD-21 score from baseline was also associated with higher baseline serotonin levels (p = 0.033) in escitalopram treatment arm. Furthermore, remitters to escitalopram treatment showed significant increases in the kynurenic acid (KynA)/3-hydroxykynurenine (3HK) ratio after treatment (p = 0.015). In contrast, response to desvenlafaxine treatment was not associated with any metabolite analyzed. We also confirmed a previous report that plasma serotonin levels are lower in MDD patients compared to healthy controls (p = 0.004) and that the kynurenine plasma level is negatively associated with depression symptom severity (p = 0.047).

CONCLUSIONS

In MDD patients the antidepressant response to escitalopram was positively associated with baseline serotonin levels and inversely associated with activation of the kynurenine pathway. These results appear consistent with previous literature showing that biomarker evidence of inflammation is associated with lower response to antidepressants from the selective serotonin reuptake inhibitor class. Moreover, increases in the kynurenic acid (KynA)/3-hydroxykynurenine (3HK) ratio, which previously has been characterized as a neuroprotective index, were associated with full remission under escitalopram treatment.

The Bidirectional Relationship of Depression and Inflammation: Double Trouble

Depression represents the number one cause of disability worldwide and is often fatal. Inflammatory processes have been implicated in the pathophysiology of depression. It is now well established that dysregulation of both the innate and adaptive immune systems occur in depressed patients and hinder favorable prognosis, including antidepressant responses. In this review, we describe how the immune system regulates mood and the potential causes of the dysregulated inflammatory responses in depressed patients. However, the proportion of never-treated major depressive disorder (MDD) patients who exhibit inflammation remains to be clarified, as the heterogeneity in inflammation findings may stem in part from examining MDD patients with varied interventions. Inflammation is likely a critical disease modifier, promoting susceptibility to depression. Controlling inflammation might provide an overall therapeutic benefit, regardless of whether it is secondary to early life trauma, a more acute stress response, microbiome alterations, a genetic diathesis, or a combination of these and other factors.

What does plasma CRP tell us about peripheral and central inflammation in depression?

Peripheral blood C-reactive protein (CRP) is a biomarker used clinically to measure systemic inflammation and is reproducibly increased in a subset of patients with major depressive disorder (MDD). Furthermore, increased peripheral blood CRP in MDD has been associated with altered reward circuitry and increased brain glutamate in relation with symptoms of anhedonia. Nevertheless, the relationship between peripheral CRP and other peripheral and central markers of inflammation in depressed patients has not been established. Plasma (n = 89) and CSF (n = 73) was collected from medically stable, currently unmedicated adult outpatients with MDD. Associations among plasma and CSF CRP and plasma and CSF inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF] and IL-1beta) and their soluble receptors/antagonists were examined. Relationships between plasma and CSF inflammatory markers and depressive symptoms including anhedonia and reduced motivation (RM) were also explored. Plasma CRP was correlated with multiple plasma inflammatory markers (all p < 0.05), and a strong correlation was found between plasma and CSF CRP (r = 0.855, p < 0.001). CSF CRP in turn correlated with CSF cytokine receptors/antagonists (all p < 0.05). Principal component analyses revealed clusters of CSF inflammatory markers that were associated with high plasma CRP (>3 mg/L) and correlated with depressive symptom severity. These findings were driven by CSF TNF, which correlated with RM (r = 0.236, p = 0.045), and CSF IL-6 soluble receptor, which correlated with anhedonia (r = 0.301, p = 0.010) in the sample as a whole and particularly females. CRP appears to be a peripheral biomarker that reflects peripheral and central inflammation and seems well-suited for guiding immunotherapies targeting TNF and IL-6 in patients with MDD.

Cardiometabolic risk in young adults with depression and evidence of inflammation: A birth cohort study

BACKGROUND

Young adults with depression and evidence of inflammation may represent a high-risk group for cardiometabolic disorders, but studies of cardiometabolic risk in this population are scarce. We aimed to examine: (1) the prevalence of low-grade inflammation in young-adults with depression; (2) cross-sectional and longitudinal associations between cardiometabolic risk factors and depression with or without evidence of inflammation.

METHOD

The ALSPAC birth cohort participants were assessed for depression and serum high-sensitivity C-Reactive Protein (CRP) levels at age 18, alongside cardiometabolic measures (fasting insulin, fasting plasma glucose, low-density lipoprotein, high-density lipoprotein, triglycerides, smoking, alcohol intake) at age 18 years, and body mass index at ages 9, 13 and 18 years. Low-grade inflammation was defined as CRP>3 mg/L. Multinomial regression was used to examine associations of cardiometabolic markers with depression cases with and without evidence of inflammation. Sensitivity analyses were conducted to examine for interactions between depression, inflammation and cardiometabolic traits.

RESULTS

Out of 2932 participants, 215 met ICD-10 criteria for depressive episode at age 18 years; 23 (10.7 %) had CRP>3 mg/L and 57 (26.5 %) had CRP 1-3 mg/L. Depressive episode with raised CRP (>3 mg/L) was associated with higher triglycerides (adjusted OR = 2.09; 95 % C.I., 1.35-3.24), higher BMI (adjusted OR = 1.13; 95 % C.I., 1.05-1.22) and insulin insensitivity (adjusted OR = 1.12; 95 % C.I., 1.01-1.26), and longitudinally with higher BMI at ages 9 (adjusted OR = 1.27; 95 % C.I., 1.10-1.48) and 13 (adjusted OR = 1.23; 95 % C.I., 1.09-1.38). There was evidence for interaction between BMI and CRP for the risk of depression at age 18 (adjusted OR for the interaction term = 1.56; 95 % C.I. 0.98-2.02) and between CRP and depressive symptoms for the risk of increased BMI at age 18 (adjusted β for the interaction term = 0.05; 95 % C.I. 0.00-0.12).

CONCLUSIONS

A notable proportion of young adults with depression have evidence of inflammation. These individuals are at increased risk of cardiometabolic disorders. Management of cardiometabolic risk in depressed individuals with evidence of inflammation should form part of routine clinical practice.

Drug repositioning for psychiatric and neurological disorders through a network medicine approach

Psychiatric and neurological disorders (PNDs) affect millions worldwide and only a few drugs achieve complete therapeutic success in the treatment of these disorders. Due to the high cost of developing novel drugs, drug repositioning represents a promising alternative method of treatment. In this manuscript, we used a network medicine approach to investigate the molecular characteristics of PNDs and identify novel drug candidates for repositioning. Using IBM Watson for Drug Discovery, a powerful machine learning text-mining application, we built knowledge networks containing connections between PNDs and genes or drugs mentioned in the scientific literature published in the past 50 years. This approach revealed several drugs that target key PND-related genes, which have never been used to treat these disorders to date. We validate our framework by detecting drugs that have been undergoing clinical trial for treating some of the PNDs, but have no published results in their support. Our data provides comprehensive insights into the molecular pathology of PNDs and offers promising drug repositioning candidates for follow-up trials.

Pathogenic contribution of the Macrophage migration inhibitory factor family to major depressive disorder and emerging tailored therapeutic approaches

BACKGROUND

Immunoinflammatory disorders are often accompanied by depression. Here, we review the available preclinical and clinical studies suggesting a role for the pro-inflammatory cytokine Macrophage migration inhibitory factor (MIF) and the second member of the MIF family, D-dopachrome tautomerase (D-DT; DDT), in the pathogenesis of Major Depressive Disorders (MDD).

METHODS

We prepared a narrative review from a search on PubMed of studies pertaining to MDD and MIF, as for October 2019. Both humans and animal studies haves been considered.

RESULTS

Preclinical data show conflicting results on the role of endogenous MIF and DDT in depression. In contrast, several human studies show that circulating MIF levels tend to increase during the course of MDD. Higher levels of inflammatory biomarkers have also been associated with poorer responses to antidepressants and the levels of MIF significantly decrease after treatment, despite this may not be necessarily associated to an improvement in psychiatric symptoms.

LIMITATIONS

This is a narrative and not a systematic review of the literature on the involvement of MIF in MDD. We have highlighted studies performed in humans and in animal models, irrespective of population size and methodological approach.

CONCLUSIONS

This review highlights a role of MIF, and possibly DDT, in the pathogenesis of MDD. Whilst studies in animal models are discordant, the studies in patients with MDD convergently suggest that MIF plays a role in induction and maintenance of the disease. Additional studies are also needed on DDT that often displays synergistic function with MIF and their receptors.

Neuroimaging as a Tool for Individualized Treatment Choice in Depression: the Past, the Present and the Future

Purpose of Review

This paper aims to review the findings on neuroimaging as a tool for facilitating individualized treatment choice in depression.

Recent Findings

Neuroimaging has allowed the exploration of neural candidates for response biomarkers. In less than two decades, the field has expanded from small single drug studies to large multisite initiatives testing multiple interventions; from simple analytical methods to employing artificial intelligence, with an aim of establishing models based on a variety of data, such as neuroimaging, biological, psychological and clinical measures.

Summary

Neural biomarkers of response may play an important role in treatment response prediction. It seems likely that they will need to be considered together with other types of data in complex models in order to achieve the high accuracy and generalizability of results necessary for clinical use.

Peripheral cytokine levels and response to antidepressant treatment in depression: a systematic review and meta-analysis

Predicting antidepressant treatment response has been a clinical challenge for major depressive disorder (MDD). The inflammation hypothesis of depression suggests that cytokines play a key role in the pathophysiology of MDD and alterations in peripheral cytokine levels are associated with antidepressant treatment outcome. Present meta-analysis aimed to examine the association between baseline peripheral cytokine levels and the response to antidepressant treatment and to evaluate whether changes of cytokine levels were associated with the response to antidepressant treatment in patients with MDD. Human-based studies published in any language in peer-reviewed journals were systematically searched from the PubMed, Embase and Web of Science databases, from inception up to October 2018. The search terms included cytokine, depressive disorder and antidepressant and their synonyms. Case-control or case-case studies reporting on levels of IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, CRP, TNF-α, IFN-γ, GM-CSF, MIP-1α, and Eotaxin-1 in patients with MDD based on validated depression scales both before and after antidepressant treatment were included. Of 7408 identified records, 44 studies met inclusion. Standardized mean differences in each cytokine were evaluated, and random-effects meta-analyses were performed. MDD patients who responded to antidepressant treatment had lower baseline IL-8 levels than the nonresponders (Hedge's g = -0.28; 95%CI, -0.43 to -0.13; P = 0.0003; FDR = 0.004). Antidepressant treatment significantly decreased levels of TNF-α (Hedge's g = 0.60; 95%CI, 0.26-0.94; P = 0.0006; FDR = 0.004) only in responders, and responders showed significantly more decreased TNF-α levels compared with nonresponders (P = 0.046). These findings suggested that alterations in peripheral cytokine levels were associated with antidepressant treatment outcomes in MDD. Further investigations are warranted to elucidate sources of heterogeneity and examine the potentiality of using inflammatory cytokines as novel predictive markers for the pharmacological treatment of MDD.

C-reactive protein and response to lurasidone treatment in children and adolescents with bipolar I depression: Results from a placebo-controlled trial

This study sought to investigate associations between levels of high-sensitivity c-reactive protein (hsCRP) prior to treatment and change in depressive symptoms and cognition in a short-term, double-blind, placebo-controlled study of lurasidone in children and adolescents with bipolar I depression. Patients 10-17 years of age with a DSM-5 diagnosis of bipolar I depression were randomized to 6 weeks of double-blind treatment with flexibly dosed lurasidone (20-80 mg/day) (n = 173) or placebo (n = 170). The primary efficacy measure was change from baseline to week 6 in the Children's Depression Rating Scale, Revised (CDRS-R). Treatment response was defined as 50% or greater improvement on the CDRS-R from baseline to week 6. Cognitive function was evaluated with the computerized Brief Cogstate Battery at baseline and week 6. Analyses were adjusted for baseline BMI, as well as age. HsCRP was evaluated as a logarithmically transformed continuous variable and as a categorical variable dichotomized into lower (<1 mg/L) and higher (≥1 mg/L) subgroups. A significant interaction was found between baseline hsCRP and treatment group for change in CDRS-R score at study endpoint, with larger placebo-corrected effect sizes for lurasidone in the higher baseline hsCRP group (≥1 mg/L). A significant BMI-by-hsCRP-by-treatment interaction was found for response rate with higher baseline hsCRP levels associated with greater antidepressant response to lurasidone (vs. placebo) in the normal BMI range subgroup (NNT = 2 in higher hsCRP vs. NNT = 5 in lower hsCRP groups) but not in the overweight/obese patients (NNT = 6 in higher hsCRP vs. NNT = 5 in lower hsCRP). Similarly, a significant interaction effect was observed for the combination of hsCRP and BMI on the procognitive effect of lurasidone, with higher baseline hsCRP levels being associated with improvement in cognitive function for lurasidone (vs placebo) in the normal BMI range subgroup but not in overweight/obese patients. These results suggest that young patients with bipolar depression with normal weight and higher levels of pre-treatment CRP may show a greater placebo-adjusted improvement in depressive symptoms and cognitive performance when treated with lurasidone. If these findings are confirmed in future prospective studies, CRP and BMI may prove to be useful diagnostic and predictive biomarkers in the treatment with lurasidone of children and adolescents with bipolar depression.

Curcumin in Depression: Potential Mechanisms of Action and Current Evidence-A Narrative Review

Major depressive disorder (MDD) is one of the most prevalent and debilitating disorders. Current available treatments are somehow limited, so alternative therapeutic approaches targeting different biological pathways are being investigated to improve treatment outcomes. Curcumin is the main active component in the spice turmeric that has been used for centuries in Ayurvedic medicine to treat a variety of conditions, including anxiety and depressive disorders. In the past decades, curcumin has drawn researchers' attention and displays a broad range of properties that seem relevant to depression pathophysiology. In this review, we break down the potential mechanisms of action of curcumin with emphasis on the diverse systems that can be disrupted in MDD. Curcumin has displayed, in a number of studies, a potency in modulating neurotransmitter concentrations, inflammatory pathways, excitotoxicity, neuroplasticity, hypothalamic-pituitary-adrenal disturbances, insulin resistance, oxidative and nitrosative stress, and endocannabinoid system, all of which can be involved in MDD pathophysiology. To date, a handful of clinical trials have been published and suggest a benefit of curcumin in MDD. With evidence that is progressively growing, curcumin appears as a promising alternative option in the management of MDD.

Novel neuroimmunologic therapeutics in depression: A clinical perspective on what we know so far

Depression, one of the most common mental health disorders, is among the leading causes of health-related disability worldwide. Although antidepressant treatment has been available for decades, depression remains largely refractory to the prevailing limited treatment approach of monoamine transmission modulation. Fortunately, recent evidence points to a link between depression and inflammatory factors within the innate and the adaptive immune system. The purpose of this review is to evaluate current and potential clinical immunotherapies for depression, as contextually focused by an immunologic lens of the pathophysiologic mechanisms of depression. The utility of pro-inflammatory cytokines (primarily interleukin-1β, interleukin -6 and tumor necrosis factor-α) is considered in their role as screening biomarkers in prediction of treatment response or nonresponse. The evidence base of numerous recent clinical studies is discussed as related to their antidepressant efficacy and favorable safety profile, with consideration of multiple agents that target inflammatory mechanisms linked to depression including nonsteroidal anti-inflammatory pathways (i.e., aspirin, celecoxib), cytokine antagonism (i.e., etanercept, infliximab), N-methyl-D-aspartate receptor (NMDA) receptor antagonism (i.e., ketamine), and modulation of kynurenine pathways (i.e., minocycline). Additionally, new and exciting directions in targeting inflammatory mechanisms in the treatment of depression are underway, and future investigation is also warranted to explore the utility of inflammation in diagnosing depression, guiding clinical treatment decision-making, and monitoring disease burden and relapse risk.

Higher S100B Levels Predict Persistently Elevated Anhedonia with Escitalopram Monotherapy Versus Antidepressant Combinations: Findings from CO-MED Trial

Background: Elevated S100 calcium binding protein B (S100B) levels in systemic circulation may induce neuroinflammation and reflect greater blood–brain barrier (BBB) dysfunction. Neuroinflammation in patients with major depressive disorder (MDD), in turn, may reduce likelihood of improvement with serotonergic antidepressants. Methods: Levels of S100B were measured in plasma samples obtained prior to initiation of treatment with bupropion-plus-escitalopram, escitalopram-plus-placebo, or venlafaxine-plus-mirtazapine in participants of Combining Medications to Enhance Depression Outcomes trial (n = 153). Depression severity was measured with 16-item Quick Inventory of Depressive Symptomatology Self-Report and anhedonia was measured with 3 items of 30-item Inventory of Depressive Symptomatology. Differential changes in depression severity and anhedonia over acute-phase (baseline, weeks 1, 2, 4, 6, 8, 10, and 12) in the three treatment arms were tested with logS100B-by-treatment-arm interaction in mixed model analyses after controlling for age, gender, and body mass index. Results: There was a significant logS100B-by-treatment-arm interaction for anhedonia (F = 3.21; df = 2, 142; p = 0.04) but not for overall depression severity (F = 1.99; df = 2, 142; p = 0.14). Higher logS100B levels were associated with smaller reductions in anhedonia (effect size = 0.67, p = 0.047) in escitalopram monotherapy but not in the other two arms. Correlation coefficients of anhedonia severity averaged over acute-phase (including baseline) with baseline S100B levels were 0.57, −0.19, and 0.22 for escitalopram monotherapy, bupropion-plus-escitalopram and venlafaxine-plus-mirtazapine arms respectively. Conclusion: Higher baseline S100B levels in depressed patients resulted in poorer response to escitalopram monotherapy. Addition of bupropion, a dopaminergic antidepressant, partially mitigated this effect.

Depression, GABA, and Age Correlate with Plasma Levels of Inflammatory Markers

Immunomodulation is increasingly being recognised as a part of mental diseases. Here, we examined whether levels of immunological protein markers changed with depression, age, or the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). An analysis of plasma samples from patients with a major depressive episode and control blood donors (CBD) revealed the expression of 67 inflammatory markers. Thirteen of these markers displayed augmented levels in patients compared to CBD. Twenty-one markers correlated with the age of the patients, whereas 10 markers correlated with the age of CBD. Interestingly, CST5 and CDCP1 showed the strongest correlation with age in the patients and CBD, respectively. IL-18 was the only marker that correlated with the MADRS-S scores of the patients. Neuronal growth factors (NGFs) were significantly enhanced in plasma from the patients, as was the average plasma GABA concentration. GABA modulated the release of seven cytokines in anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs) from the patients. The study reveals significant changes in the plasma composition of small molecules during depression and identifies potential peripheral biomarkers of the disease.

Inflammatory and metabolic disturbances are associated with more severe trajectories of late-life depression

Late-life depression is a highly prevalent mental health condition with devastating consequences even from its earliest stages. Alterations in physiological functions, such as inflammatory and metabolic, have been described in patients with depression. However, little is known on the association between depression symptom course and metabolic and inflammation dysregulation. This study aimed to depict the course of depression symptoms while ageing, taking into consideration inter-individual heterogeneity. Moreover, it intended to study the associations between inflammatory and metabolic risk profiles and symptom trajectories. To do so, data from 13,203 adults aged 50-90 years (52.75% women; mean age at baseline = 65.07, SD = 10.00) were used. Blood sample and blood pressure measures were taken from 1536 participants (56.58% women; mean age at baseline = 61.73 years, sd = 7.64). Depression symptoms were assessed every two years across a 10-year follow-up. Trajectories were identified by means of latent class mixed modelling. Inflammation and metabolic risk profile scores were obtained from plasma and diagnostic-based indicators in the follow-up, using a robust latent-factor approach. Multigroup modelling was used to study the associations between the profiles and symptom trajectories. As a result, three heterogeneous trajectories of symptoms were identified (low-symptom, moderate-symptom and high-symptom trajectory). Participants depicting a high-symptom trajectory showed the greatest inflammation profile score and high metabolic risk. Moderate-symptom trajectory was also related to high inflammation and metabolic risk. To sum up, at-risk trajectories of symptoms were associated with high inflammation and risk of metabolic diseases. This study provides valuable evidence to advance personalised medicine and mental health precision, considering person-specific profiles and physiological concomitants.

C-Reactive Protein Gene Variants in Depressive Symptoms & Antidepressants Efficacy

OBJECTIVE

Although the pathogenesis of depression remains unclear, C-reactive protein (CRP) levels are commonly elevated in depressed patients. Thus, CRP single-nucleotide polymorphisms (SNPs) that influence CRP levels may be associated with depression. In the present study, we explored whether CRP SNPs are related to depressive symptoms and antidepressants efficacy in Han Chinese patients.

METHODS

We analyzed data from 440 patients with first-episode depression. We obtained genome CRP SNPs, scores of the 17-item Hamilton Rating Scale for Depression 17 (HAMD17) and its four-factor at baseline and after 6 weeks. Quantitative trait analysis was performed using UNPHASED software and curative effects were analyzed using SPSS software.

RESULTS

Male patients with SNP rs1800947G exhibited lower insomnia scores and rs2794521CC exhibited lower scores of anxiety/ physical symptoms, total HAMD17 score. Female patients with rs2794521TT exhibited higher scores of insomnia and lower antidepressants efficacy.

CONCLUSION

CRP SNPs rs1800947 and rs2794521 may be associated with depressive symptoms in patients with depression in a sexspecific fashion. Furthermore, rs2794521 may be a predictor of the efficacy of antidepressants in female patients.

Kynurenine metabolism and inflammation-induced depressed mood: A human experimental study

Inflammation has an important physiological influence on mood and behavior. Kynurenine metabolism is hypothesized to be a pathway linking inflammation and depressed mood, in part through the impact of kynurenine metabolites on glutamate neurotransmission in the central nervous system. This study evaluated whether the circulating concentrations of kynurenine and related compounds change acutely in response to an inflammatory challenge (endotoxin administration) in a human model of inflammation-induced depressed mood, and whether such metabolite changes relate to mood change. Adults (n = 115) were randomized to receive endotoxin or placebo. Mood (Profile of Mood States), plasma cytokine (interleukin-6, tumor necrosis factor-α) and metabolite (kynurenine, tryptophan, kynurenic acid, quinolinic acid) concentrations were repeatedly measured before the intervention, and at 2 and 6 h post-intervention. Linear mixed models were used to evaluate relationships between mood, kynurenine and related compounds, and cytokines. Kynurenine, kynurenic acid, and tryptophan (but not quinolinic acid) concentrations changed acutely (p's all <0.001) in response to endotoxin as compared to placebo. Neither kynurenine, kynurenic acid nor tryptophan concentrations were correlated at baseline with cytokine concentrations, but all three were significantly correlated with cytokine concentrations over time in response to endotoxin. Quinolinic acid concentrations were not correlated with cytokine concentrations either before or following endotoxin treatment. In those who received endotoxin, kynurenine (p = 0.049) and quinolinic acid (p = 0.03) positively correlated with depressed mood, although these findings would not survive correction for multiple testing. Changes in tryptophan and kynurenine pathway metabolites did not mediate the relationship between cytokines and depressed mood. Further work is necessary to clarify the pathways leading from inflammation to depressed mood in humans.

The Prospective Association Between Inflammation and Depressive Symptoms in Type 2 Diabetes Stratified by Sex

OBJECTIVE

We tested whether inflammation is associated with worsening depressive symptoms in type 2 diabetes and examined whether sex moderated this association.

RESEARCH DESIGN AND METHODS

In a prospective cohort study of people with newly diagnosed type 2 diabetes, we measured depressive symptoms over a 2-year follow-up using the Patient Health Questionnaire-9 (PHQ-9). The independent variable was a composite inflammation burden score at diagnosis of diabetes, derived from hs-CRP, white cell count, interleukin (IL)-1β, IL-1 receptor antagonist, monocyte chemotactic protein-1, and vascular endothelial growth factor concentrations. General linear models assessed 1) the association between overall inflammation burden and estimated marginal mean PHQ-9 score (ln transformed) at 2 years and 2) whether sex interacted with elevated inflammation burden (above-median score) in predicting change in PHQ-9 score. Models were adjusted for age, ethnicity, BMI, blood pressure, cholesterol, HbA_1c, antidepressants, anti-inflammatory medications, and baseline ln PHQ-9 score.

RESULTS

Of 1,174 people with complete inflammation data, mean (SD) age was 56.7 (11.0) years and 46.1% were of nonwhite ethnicity and 44.1% female. After full adjustment, inflammation burden was not associated with worsening ln PHQ-9 score (P = 0.65). However, female sex interacted with elevated inflammation in predicting higher 2-year ln PHQ-9 score (β = 0.32, P = 0.005), showing that the difference by inflammation burden in females was 0.32 larger than in males. In post hoc comparisons, ln PHQ-9 score was higher in females than males with elevated inflammation (P = 0.003) but not with low inflammation (P = 0.34) burden.

CONCLUSIONS

In type 2 diabetes, female sex confers specific vulnerability to the effects of inflammation on depressive symptoms.

Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels

BACKGROUND

Peripheral low-grade inflammation in depression is increasingly seen as a therapeutic target. We aimed to establish the prevalence of low-grade inflammation in depression, using different C-reactive protein (CRP) levels, through a systematic literature review and meta-analysis.

METHODS

We searched the PubMed database from its inception to July 2018, and selected studies that assessed depression using a validated tool/scale, and allowed the calculation of the proportion of patients with low-grade inflammation (CRP >3 mg/L) or elevated CRP (>1 mg/L).

RESULTS

After quality assessment, 37 studies comprising 13 541 depressed patients and 155 728 controls were included. Based on the meta-analysis of 30 studies, the prevalence of low-grade inflammation (CRP >3 mg/L) in depression was 27% (95% CI 21-34%); this prevalence was not associated with sample source (inpatient, outpatient or population-based), antidepressant treatment, participant age, BMI or ethnicity. Based on the meta-analysis of 17 studies of depression and matched healthy controls, the odds ratio for low-grade inflammation in depression was 1.46 (95% CI 1.22-1.75). The prevalence of elevated CRP (>1 mg/L) in depression was 58% (95% CI 47-69%), and the meta-analytic odds ratio for elevated CRP in depression compared with controls was 1.47 (95% CI 1.18-1.82).

CONCLUSIONS

About a quarter of patients with depression show evidence of low-grade inflammation, and over half of patients show mildly elevated CRP levels. There are significant differences in the prevalence of low-grade inflammation between patients and matched healthy controls. These findings suggest that inflammation could be relevant to a large number of patients with depression.

Changes in inflammation with treatment for bipolar II depression: Pilot trial data on differential effects of psychotherapy and medication

OBJECTIVES

Limited prospective data, mostly focused on bipolar I disorder, suggests that pro-inflammatory cytokines are elevated in abnormal mood states. We evaluated whether treatment normalizes peripheral markers of inflammation in bipolar II disorder.

METHODS

Using data from a randomized clinical trial of Interpersonal and Social Rhythm Therapy (IPSRT) + quetiapine vs. IPSRT + placebo for bipolar II depression, we examined whether these treatments for bipolar II depression impact inflammatory cytokines and whether observed changes in cytokines are associated with changes in depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD-17).

RESULTS

Cytokine values were available for 33 participants who completed baseline and 20-week followup visits. After excluding those with CRP values >=10 mg/L, there were 27 patients available for analysis (IPSRT+quetiapine N=10, IPSRT+placebo N=17). Baseline measure of inflammation did not appear to moderate treatment response, nor was change in HRSD-17 score correlated with changes in cytokines. Those who received IPSRT+quetiapine had significantly greater increases in IL-6 (p=0.02) and TNF-α (p=0.04), even after adjusting for changes in body mass index, than the IPSRT alone group. Descriptively, the quetiapine group showed increases in pro-inflammatory and decreases in anti-inflammatory cytokines and the psychotherapy group showed reduced pro-inflammatory cytokines.

CONCLUSIONS

Despite both groups showing depression improvement, this small study suggests a more pro-inflammatory cytokine profile over time with quetiapine plus psychotherapy compared to psychotherapy alone. Elevated risk of cardiovascular morbidity and mortality among those with bipolar II disorder underscores the importance of delivering treatments that do not exacerbate these risk factors.

Treatment response classes in major depressive disorder identified by model-based clustering and validated by clinical prediction models

The identification of generalizable treatment response classes (TRC[s]) in major depressive disorder (MDD) would facilitate comparisons across studies and the development of treatment prediction algorithms. Here, we investigated whether such stable TRCs can be identified and predicted by clinical baseline items. We analyzed data from an observational MDD cohort (Munich Antidepressant Response Signature [MARS] study, N = 1017), treated individually by psychopharmacological and psychotherapeutic means, and a multicenter, partially randomized clinical/pharmacogenomic study (Genome-based Therapeutic Drugs for Depression [GENDEP], N = 809). Symptoms were evaluated up to week 16 (or discharge) in MARS and week 12 in GENDEP. Clustering was performed on 809 MARS patients (discovery sample) using a mixed model with the integrated completed likelihood criterion for the assessment of cluster stability, and validated through a distinct MARS validation sample and GENDEP. A random forest algorithm was used to identify prediction patterns based on 50 clinical baseline items. From the clustering of the MARS discovery sample, seven TRCs emerged ranging from fast and complete response (average 4.9 weeks until discharge, 94% remitted patients) to slow and incomplete response (10% remitted patients at week 16). These proved stable representations of treatment response dynamics in both the MARS and the GENDEP validation sample. TRCs were strongly associated with established response markers, particularly the rate of remitted patients at discharge. TRCs were predictable from clinical items, particularly personality items, life events, episode duration, and specific psychopathological features. Prediction accuracy improved significantly when cluster-derived slopes were modelled instead of individual slopes. In conclusion, model-based clustering identified distinct and clinically meaningful treatment response classes in MDD that proved robust with regard to capturing response profiles of differently designed studies. Response classes were predictable from clinical baseline characteristics. Conceptually, model-based clustering is translatable to any outcome measure and could advance the large-scale integration of studies on treatment efficacy or the neurobiology of treatment response.

Mechanisms and treatment of late-life depression

Depression predisposes to medical illnesses and advances biological aging indicated by shorter telomere length, accelerated brain aging and advanced epigenetic aging. Medical illnesses also increase the risk of late-life depression. The reciprocal relationships of depression with aging-related and disease-related processes have generated pathogenetic hypotheses and provided treatment targets. Targeting risk factors of vascular disease in mid-life is a logical approach in prevention of vascular depression. The depression-executive dysfunction and the vascular depression syndromes have clinical presentations and neuroimaging findings consistent with frontostriatal abnormalities. Dopamine D_2/3 agonists are effective in depression of Parkinson's disease and their efficacy needs to be assessed in these two syndromes. Computerized cognitive remediation targeting functions of the cognitive control network may improve both executive functions and depressive symptoms of late-life major depression. Significant progress has been made in neurostimulation treatments in depressed younger adults. TMS targeting deep structures responsible for mood regulation is well tolerated by older adults and its efficacy in syndromes of late-life depression needs to be studied. Efficacious psychotherapies for late-life depression exist, but are underutilized in part because of their complexity. Streamlined, stepped psychotherapies targeting behaviors assumed to result from dysfunction of brain networks implicated in late-life depression can be easy to learn and have potential for dissemination. However, their effectiveness needs further investigation. Depression increases the risk of dementing disorders. Antidepressants are rather ineffective in treating depression of demented patients, but long-term use of antidepressants may reduce the risk of dementia. However, confirmation studies are needed.

Biomarkers for response in major depression: comparing paroxetine and venlafaxine from two randomised placebo-controlled clinical studies

The identification of biomarkers of response might speed drug development and set the premises to assist clinical practice in psychiatry. In this work, we evaluated a panel of peripheral biomarkers (including IL-6, IL-10, TNF-α, TNFRII, BDNF, CRP, MMP9 and PAI1) in depressed patients receiving paroxetine, venlafaxine, or placebo. Samples were obtained from two randomised placebo-controlled studies evaluating the efficacy and tolerability of a novel drug candidate, using either paroxetine or venlafaxine as active comparators. In both studies, the biomarker candidates were analysed in plasma collected at randomization and after 10 weeks of treatment with either placebo or active comparator (for a total of 106 and 108 subjects in the paroxetine and venlafaxine study, respectively). Data were obtained by multiplexing sandwich-ELISA system. Data were subjected to statistical analysis to assess their correlation with baseline severity and with response outcome. Increases in biomarker levels were correlated with reduction in depression severity for TNF-α, IL-6 IL-10 and CRP. Response to paroxetine treatment correlated with baseline IL-10, IL-6 and TNF-α levels, with the strongest signal being observed in males. In the venlafaxine study, a correlation was observed only between CRP level at randomisation and response, suggesting differences between the two active treatments and the two studies. Our investigations suggest that a combination of pro- and anti-inflammatory cytokines may predict response outcome in patients treated with paroxetine. The potential for IL-10, IL-6 and TNF-α as response biomarkers for a wider range of antidepressants warrants further investigations in clinical trials with other monoamine reuptake inhibitors.

Correlation between white blood cell count and mood-stabilising treatment response in two bipolar disorder trials

BACKGROUND

Immune system markers may predict affective disorder treatment response, but whether an overall immune system marker predicts bipolar disorder treatment effect is unclear.

METHODS

Bipolar CHOICE (N = 482) and LiTMUS (N = 283) were similar comparative effectiveness trials treating patients with bipolar disorder for 24 weeks with four different treatment arms (standard-dose lithium, quetiapine, moderate-dose lithium plus optimised personalised treatment (OPT) and OPT without lithium). We performed secondary mixed effects linear regression analyses adjusted for age, gender, smoking and body mass index to investigate relationships between pre-treatment white blood cell (WBC) levels and clinical global impression scale (CGI) response.

RESULTS

Compared to participants with WBC counts of 4.5-10 × 109/l, participants with WBC &lt; 4.5 or WBC ≥ 10 showed similar improvement within each specific treatment arm and in gender-stratified analyses.

CONCLUSIONS

An overall immune system marker did not predict differential treatment response to four different treatment approaches for bipolar disorder all lasting 24 weeks.

Factor analyses differentiate clinical phenotypes of idiopathic and interferon-alpha-induced depression

The discovery that prolonged administration of interferon-alpha (a pro-inflammatory cytokine) readily precipitates depressive symptoms has played a key role in development of the inflammation theory of major depressive disorder (MDD). However, it remains unclear whether the clinical phenotype of patients with inflammation-associated depression significantly overlaps with, or can be distinguished from that of patients with 'idiopathic' depression. Here we explored the Hamilton depression scale factor structure of 172 patients undergoing interferon-alpha treatment for hepatitis-C at the point of transition to a depressive episode of DSM IV defined major depression severity. The resulting factor structure was first compared with a model derived from 6 previous studies of 'idiopathic' MDD (Cole et al., 2004). This confirmatory factor analysis revealed that the factor structure of HAMD scores in our interferon-alpha treated cohort did not plausibly fit that previously described for 'idiopathic' MDD. Instead, subsequent exploratory factor analysis revealed a distinct four factor model with a novel primary factor grouping cognitive symptoms of depression and anxiety (HAMD items 1, 2, 9, 10, 11, 15). The second sleep disorder factor (items 4, 5, 6) replicated previous findings in 'idiopathic' depression. A third and unique factor grouped somatic symptoms and function (items 7, 12, 13, 14 and item 1). The final factor (also common in idiopathic depression studies), grouped gastrointestinal symptoms and weight loss (items 12 and 16). Severe depression items (3, 8, and 17) were excluded from analysis due to very low variance. At transition, interferon-alpha induced major depressive episodes therefore appears to have more associated anxiety features that covary with depressed mood than classical or 'idiopathic' MDD and a low likelihood of severe features such as suicidal ideation. Identification of this clinical phenotype may help identify patients with an inflammatory depression etiology and support the development of more effective and personalized therapies.

The Role of Inflammation in Depression and Fatigue

Depression and fatigue are conditions responsible for heavy global societal burden, especially in patients already suffering from chronic diseases. These symptoms have been identified by those affected as some of the most disabling symptoms which affect the quality of life and productivity of the individual. While many factors play a role in the development of depression and fatigue, both have been associated with increased inflammatory activation of the immune system affecting both the periphery and the central nervous system (CNS). This is further supported by the well-described association between diseases that involve immune activation and these symptoms in autoimmune disorders, such as multiple sclerosis and immune system activation in response to infections, like sepsis. Treatments for depression also support this immunopsychiatric link. Antidepressants have been shown to decrease inflammation, while higher levels of baseline inflammation predict lower treatment efficacy for most treatments. Those patients with higher initial immune activation may on the other hand be more responsive to treatments targeting immune pathways, which have been found to be effective in treating depression and fatigue in some cases. These results show strong support for the hypothesis that depression and fatigue are associated with an increased activation of the immune system which may serve as a valid target for treatment. Further studies should focus on the pathways involved in these symptoms and the development of treatments that target those pathways will help us to better understand these conditions and devise more targeted treatments.

SCI and depression: Does inflammation commandeer the brain?

The incidence of depression is almost twice as high in the spinally injured population compared to the general population. While this incidence has long been attributed to the psychological, economic, and social burdens that accompany spinal cord injury (SCI), data from animal studies indicate that the biology of SCI may play an important role in the development of depression. Inflammation has been shown to impact stress response in rodents and humans, and inflammatory cytokines have been associated with depression for decades. The inflammation inherent to SCI may disrupt necessary mechanisms of mental homeostasis, such as serotonin production, dopamine production, and the hypothalamic pituitary adrenal axis. Additionally, gut dysbiosis that occurs after SCI can exacerbate inflammation and may cause further mood and behavior changes. These mediators combined may significantly contribute to the rise in depression seen after SCI. Currently, there are no therapies specific to depression after SCI. Elucidation of the molecular pathways that contribute to SCI-specific depression is crucial for the understanding of this disease and its potential treatments.

Predictors of response and remission in a naturalistic inpatient sample undergoing multimodal treatment for depression

BACKGROUND

Many depressed patients do not achieve response or remission despite adequate treatment. Identifying predictors of outcome can contribute to developing therapeutic algorithms for difficult-to-treat depression. Therefore, we examined clinical predictors of response and remission in a naturalistic inpatient sample undergoing multimodal treatment for depression.

METHODS

Three hundred and fifty-one consecutive inpatients admitted to a tertiary care university hospital (specialized psychiatry unit for treatment of unipolar and bipolar depression) between January 2014 and December 2016 were characterized by a set of sociodemographic and clinical variables. The predictive value of these variables for response (≥ 50% decrease from baseline Montgomery-Åsberg Depression Rating Scale (MADRS) score) and remission (MADRS score at discharge < 10) were explored using bivariate analysis and logistic regression.

RESULTS

Greater symptom severity and fewer psychotropic medications at the time of admission predicted response. Remission rates were higher for patients with non-chronic depression, higher number of previous depressive episodes, fewer psychotropic medications and less severe depression at admission.

LIMITATIONS

This was a retrospective study without a control group. The sample was drawn from a single inpatient ward specialized for difficult-to-treat depression.

CONCLUSIONS

Greater baseline depression severity might be a proxy for a less chronic course of depression thereby explaining its association with greater response rates. Fewer episodes in the past and polypharmacy could indicate treatment-resistance and chronicity, contributing to lower remission rates. Therefore, preventing chronicity should be a central aim of depression treatment.

Sex differences in the association of baseline c-reactive protein (CRP) and acute-phase treatment outcomes in major depressive disorder: Findings from the EMBARC study

Peripheral inflammation is associated with poor response to antidepressant treatments. However, whether sex differentially affects this association remains unknown. Participants of Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care (EMBARC) with baseline plasma samples were included in this study (n = 220; male n = 75, female n = 145). Depression severity [Hamilton Rating Scale for Depression 17-item (HAMD-17)] was measured at baseline and weeks- 1, 2, 3, 4, 6, and 8. Plasma c-reactive protein (CRP) was measured with commercially-available ELISA kits at baseline, week-1, and week-8. Sex difference in prediction of baseline-to-week-8 HAMD-17 change by baseline CRP was tested with sex-by-baseline-CRP-by-time interaction in mixed model analysis. Additionally, changes in CRP from baseline-to-week-8 CRP and its association with HAMD-17 changes over that period were also evaluated. Covariates included body mass index, site, smoking status, and age. There was a significant sex difference in association of baseline-to-week-8 HAMD-17 reduction with baseline CRP (p = 0.033). Higher baseline CRP was associated with lower baseline-to-week-8 HAMD-17 reduction in females (p < 0.0001) but not in males (p = 0.632). Additionally, CRP was significantly reduced (p = 0.041, effect size = 0.254) from baseline-to-week-8, but there were no sex differences in this reduction (p = 0.249). Baseline-to-week-8 changes in HAMD-17 and CRP were not significantly associated either overall (p = 0.348) or based on sex (p = 0.370). In a large study of depressed outpatients, we replicated previous findings that elevated baseline CRP levels are associated with worse antidepressant treatment outcomes. However, this effect was limited only to females. These findings emphasize the importance of studying sex differences in biological mechanisms linking inflammation and depression.

Depression and inflammation among epidermal growth factor receptor (EGFR) mutant nonsmall cell lung cancer patients

OBJECTIVE

Depression is highly prevalent in nonsmall cell lung cancer (NSCLC) and is associated with elevated inflammation. However, certain subtypes of driver mutation-associated NSCLC such as epidermal growth factor receptor (EGFR)-mutated NSCLC may be associated with less depression given the differences in their underlying biology and disease trajectories. Biological variables such as inflammation, measured by C-reactive protein (CRP), may provide insight into depression variability in EGFR mutant NSCLC.

METHODS

Patients with EGFR mutant and wild-type metastatic NSCLC were evaluated for depression using the Hospital Anxiety and Depression Scale (HADS) on a continuous scale and meeting depression screening criteria (HADS ≥ 8). Inflammation was measured using CRP. A mediation model was created to understand how inflammation mediates EGFR wild-type associated depression.

RESULTS

One hundred out of 120 patients with NSCLC were recruited (83.3% response rate). The 20 participants with EGFR mutant NSCLC had less depression (HADS-D 3.0 versus 5.4) (P < .001), met depression screening criteria less often (P = .047), and exhibited less inflammation (CRP = 0.23 mg/mL versus 2.71 mg/mL) (P < .001) in comparison with EGFR wild-type NSCLC. Multivariate linear regression model revealed that only CRP predicted depression (P = .015) while controlling for age and sex. Mediation analysis found that lower CRP partially mediated less depression in EGFR mutant NSCLC.

CONCLUSIONS

EGFR mutant NSCLC is associated with less depression but the relationship is partially mediated by lower CRP-related inflammation, which is a stronger predictor of depression than EGFR status. Depression in lung cancer varies by subtype and is significantly related to inflammation.

Longitudinal Association Between Depression and Inflammatory Markers: Results From the Netherlands Study of Depression and Anxiety

BACKGROUND

While cross-sectional associations of inflammatory markers interleukin-6 (IL-6) and C-reactive protein with major depressive disorder are well established, evidence for longitudinal associations mostly comes from studies on depression symptoms, not diagnoses. This study examined cross-sectional and bidirectional longitudinal associations between depression diagnosis and symptoms in an adult sample over a 6-year period.

METHODS

Data were obtained from the baseline (n = 2416) and 2- and 6-year follow-up assessments (n = 1925 and n = 1924, respectively) of the Netherlands Study of Depression and Anxiety. C-reactive protein and IL-6 were assessed at each wave, as were the Composite International Diagnostic Interview and Inventory of Depressive Symptomatology. Linear mixed models and generalized estimating equation models with a binomial distribution were used to study longitudinal associations between depression and inflammation and vice versa.

RESULTS

There was a consistent cross-sectional association between current depressive disorder (vs. no current disorder) and symptoms with IL-6 across all follow-up measurements (Cohen's d_{depression diagnosis} = 0.06, p = .017; B_{standardized Inventory of Depressive Symptomatology} = 0.029, SE = 0.011, p = .008). In longitudinal analyses, higher IL-6 levels predicted subsequent chronic course in those with a diagnosis at baseline in women but not in men (odds ratio_women = 1.13, 95% confidence interval = 1.04-1.23), and both depressive disorder and high severity predicted higher IL-6 levels at the subsequent follow-up (p values < .01). In contrast, C-reactive protein was not associated with current depression in cross-sectional and longitudinal analyses.

CONCLUSIONS

In this longitudinal study, cross-sectional and bidirectional longitudinal associations were found between depression and IL-6 levels. This underlines the importance of targeting inflammation pathways in the treatment of major depressive disorder. IL-6 could be a potential marker for patient profiling in personalized medicine approaches.

Efficacy of anti-inflammatory treatment on major depressive disorder or depressive symptoms: meta-analysis of clinical trials

BACKGROUND

No study has gathered evidence from all randomized clinical trials (RCTs) with anti-inflammatory drugs measuring antidepressant effects including a detailed assessment of side-effects and bias.

METHODS

We performed a systematic review identifying RCTs published prior to January 1, 2018, studying antidepressant treatment effects and side-effects of pharmacological anti-inflammatory intervention in adults with major depressive disorder (MDD) or depressive symptoms. Outcomes were depression scores after treatment, remission, response, and side-effects. Pooled standard mean differences (SMD) and risk ratios (RR) including 95% confidence intervals (95%-CI) were calculated.

RESULTS

We identified 36 RCTs, whereof 13 investigated NSAIDs (N = 4214), 9 cytokine inhibitors (N = 3345), seven statins (N = 1576), 3 minocycline (N = 151), 2 pioglitazone (N = 77), and 2 glucocorticoids (N = 59). Anti-inflammatory agents improved depressive symptoms compared to placebo as add-on in patients with MDD (SMD = -0.64; 95%-CI = -0.88, -0.40; I²  = 51%; N = 597) and as monotherapy (SMD = -0.41; 95%-CI = -0.60, -0.22; I²  = 93%, N = 8825). Anti-inflammatory add-on improved response (RR = 1.76; 95%-CI = 1.44-2.16; I²  = 16%; N = 341) and remission (RR = 2.14; 95%-CI = 1.03-4.48; I²  = 57%; N = 270). We found a trend toward an increased risk for infections, and all studies showed high risk of bias.

CONCLUSION

Anti-inflammatory agents improved antidepressant treatment effects. Future RCTs need to include longer follow-up, identify optimal doses and subgroups of patients that can benefit from anti-inflammatory intervention.

Baseline serum C-reactive protein levels may predict antidepressant treatment responses in patients with major depressive disorder

BACKGROUND

Inflammation has been shown previously to predict antidepressant treatment response. This retrospective study was conducted to test if the baseline serum C-reactive protein (CRP) levels could predict antidepressant treatment responses in a Chinese sample.

METHODS

75 adult inpatients (26 male, 49 female) with major depressive disorder (MDD) diagnosed according to DSM-5 were included in this study. Sociodemographic and clinical features, baseline CRP levels, 17-item Hamilton Depression Rating Scale (HDRS-17) and Hamilton Anxiety Rating Scale (HARS) scores assessed at baseline and weeks 1, 2, 3 and 4 were then collected. Afterwards patients were divided into two groups: the low CRP group (baseline CRP < 1 mg/L, n = 47) and the high CRP group (baseline CRP ≥ 1 mg/L, n = 28). Depression severity and treatment response were compared between the two groups.

RESULTS

Repeated-measures ANOVA showed a significant group * assessments interaction in HDRS-17 scores (F = 4.754; p = 0.005). Post-hoc test showed that the two groups differed in HDRS-17 scores at week 4 (F = 6.698; p = 0.012), with the low CRP group having lower HDRS-17 scores than the high CRP group. Moreover, the low CRP group exhibited higher percent reduction in HDRS-17 scores at week 3 (F = 5.016; p = 0.028) and week 4 (F = 9.865; p = 0.003) as compared to the high CRP group. Cox proportional hazard model showed that the remission rate was higher in the low CRP group (p = 0.010).

LIMITATIONS

Patients received uncontrolled antidepressant therapy and the sample size was limited.

CONCLUSIONS

Baseline serum CRP levels may predict antidepressant treatment responses in patients with MDD and patients with higher levels of CRP were less likely to get remission.

Depressive symptoms in inflammatory bowel disease: an extraintestinal manifestation of inflammation?

Depressive symptoms are reported by more than 20% of people with inflammatory bowel disease (IBD), while sleep difficulties and fatigue are even more common. Co-morbid depressive symptoms predict a poor IBD course, including increased risk of relapse and surgery, which is inconsistently improved by psychological treatments. Rather than being distinct systems, there is compelling evidence for bidirectional communication between gut and brain, driven by neural, metabolic, endocrine and inflammatory mediators. An emerging concept is that depressive symptoms may be mechanistically linked to excess inflammation and dysregulation of the gut-brain axis. Given the close link between the intestinal microbiota and host immune responses, patients prone to shifts in their intestinal microbiome, including smokers, those with poor diet and early life stress, may be exposed to exaggerated immune responses. Excess inflammation is associated with brain changes (depressive symptoms, fatigue, sleep difficulties) and worsening gastrointestinal symptoms, which are exacerbated by psychological distress. Equally, treatments both for depressive symptoms and IBD provide opportunities to break this cycle by reducing the causes and effects of inflammation. As well as addressing potential risk factors such as smoking and diet, treatments to alter the microbiome may reduce depressive symptoms. Observational evidence suggests that anti-inflammatory treatments for IBD may improve co-morbid depressive symptoms correlating with reduction in inflammation. With a growing range of treatments targeting inflammation centrally, peripherally and in the gut, IBD provides a unique model to understand the interplay between brain and gut in the pathogenesis of depressive symptoms, both in IBD and in the whole population.

The association between low-grade inflammation and the clinical features of bipolar disorder in Han Chinese population

Variety of evidence suggests that low-grade inflammation may be involved in the pathophysiology of bipolar disorder (BD). However, the conclusion regarding the relationship between inflammation and BD has been inconsistent. In this study, we aimed to survey the prevalence of low-grade inflammation in a large Han Chinese population with BD and assess its impact on the clinical features of BD. 430 eligible cases were drawn from patients who were admitted or had ever been admitted for BD to the inpatient service of the psychiatric department of the Third Hospital of Sun Yat-sen University. Subjects with current active physical diseases or white blood count (WBC) >19.0 × 10⁹/L (2 times the upper reference) were excluded. Serum C-reactive protein (CRP) levels and WBC were measured with fast blood sample. Low-grade inflammation was defined as CRP>3 mg/L or WBC > 9.5 × 10⁹/L(the upper reference). Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education. If defined as CRP>3 mg/L, the prevalence of low-grade inflammation among BD was 10.1% (41/404), it was positively associated with BMI (p = 0.012), comorbidity of glycolipid metabolic diseases(p = 0.018). After adjusting for BMI, it was found to be positively related to recent suicide attempt (p = 0.03), initiation with (hypo)manic episode(p = 0.047), leaden paralysis (p = 0.037) and family history of mental disorders(p = 0.012), while the association between comorbidity of glycolipid metabolic diseases and low-grade inflammation disappeared (p = 0.330). If defined as WBC > 9.5 × 10⁹/L, the prevalence of low-grade inflammation was 8.1% (33/409), it was positively associated with psychotic features (p = 0.011) and adverse life events before the onset of illness(p < 0.001), but was not significantly influenced by BMI (p = 0.077). A much lower prevalence of low-grade inflammation in BD is found among Han Chinese population than among western population. Low-grade inflammation of different definition impacts differentially on the clinical features of BD.

Inflammatory profiles of severe treatment-resistant depression

BACKGROUND

Treatment-resistant depression (TRD) contributes substantially to the burden of mood disorders and is undoubtedly an important subpopulation in whom there are clear unmet treatment needs. Despite a paucity of research focusing specifically on TRD, recent studies indicate that inflammatory activity may be particularly elevated in these patients.

METHODS

36 patients with TRD were investigated longitudinally before and after undertaking a specialist inpatient treatment program. 27 inflammatory proteins were compared between patients and a matched sample of non-depressed controls, as well as between treatment responders and non-responders. Treatment outcomes were calculated from depression severity scores before and after admission, and at a long-term follow-up 3-12 months after discharge.

RESULTS

TRD patients had higher levels of numerous inflammatory proteins than controls, and elevated interleukins 6 and 8, tumour necrosis factor, c-reactive protein and macrophage inflammatory protein-1 were associated with poorer treatment outcomes. A separate set of proteins (either anti-inflammatory in nature or attenuated at baseline) showed increases during treatment, regardless of clinical response. Participants with the greatest elevations in inflammation tended to be older, more cognitively impaired and more treatment-resistant at baseline.

LIMITATIONS

The small sample and large number of comparisons examined in this study must be taken into account when interpreting these results.

CONCLUSIONS

However, this study provides empirical support for theories that more severe, chronic or treatment-resistant depressive disorders are associated with dysregulated inflammatory activity. If a predictor or predictors of response in TRD are established, improved and targeted care might be more reliably provided to this vulnerable population.

Difficult-to-treat depression: A clinical and research roadmap for when remission is elusive

OBJECTIVES

The report considers the pros and cons of the most commonly used conceptual model that forms the basis for most clinical practice guidelines for depression. This model promotes the attainment of sustained symptom remission as the treatment goal based on its well-established prognostic and functional importance. Sustained remission is very unlikely, however, after multiple treatment attempts. Our current model propels many clinicians to continue to change or add treatments despite little chance for remission or full functional restoration and despite the increasing risk of more adverse events from polypharmacy. An alternative 'difficult-to-treat depression' model is presented and considered. It accepts that the treatment aims for some depressed patients may shift to optimal symptom control rather than remission. When difficult-to-treat depression is suspected, the many treatable causes of persistent depression must be assessed and addressed (given the importance of remission when attainable) before difficult-to-treat depression can be ascribed. The clinical and research implications of the difficult-to-treat depression model are discussed.

CONCLUSION

Suspected difficult-to-treat depression provides a practical basis for considering when to conduct a comprehensive evaluation. Once difficult-to-treat depression is confirmed, treatment may better focus on optimal disease management (symptom control and functional improvement).

Allicin attenuated chronic social defeat stress induced depressive-like behaviors through suppression of NLRP3 inflammasome

Allicin, one of the main biologically active compounds derived from garlic, was previously reported to possess multiple pharmacological activities. Whether allicin protected against chronic social defeat stress (CSDS) induced depressive-like behaviors remained unknown. Thus, our present study for the first time investigated the potential antidepressant effects and the mechanisms of allicin on the CSDS mice model. Thirty minutes before social defeat stress, allicin (2, 10, 50 mg/kg) was treated by intraperitoneal injection. The duration times of CSDS model establishment and allicin intervene were 10 days. Subsequently, the force swimming test (FST), social interaction test (SIT), and sucrose preference test (SPT) were applied for behavioral assessments. The levels of inflammation mediators were determined by commercial ELISA kits. The concentration of iron was tested, and relative protein expressions were measured by western blot. Oxidative stress and apoptosis markers were also detected by commercial kits and western blot. The behavioral defects induced by social defeat stress were obviously improved by allicin. Microglia activation, as well as inflammatory cytokines elevation in the hippocampus of CSDS also down-regulated by administration of allicin. Furthermore, content of iron and protein expressions of key components in iron metabolism were remarkably aberrant changed in the CSDS mice hippocampus, meanwhile, allicin ameliorated this phenomenon. Allicin decreased the production of reactive oxygen species (ROS), malondialdehyde (MDA), and protein carbonyl, and the protein expression of NOX4, as well as up-regulated the activities of superoxide dismutase (SOD) and Nrf2/HO-1 pathway. In addition, allicin attenuated the enhanced neuronal apoptosis. Finally, allicin supplementation inhibited the Nucleotide-binding oligomerization domain containing 3 (NLRP3) inflammasome hyperactivity, and the expressions of inflammasome components, such as ACS, caspase-1, and IL-1β in the hippocampus of CSDS mice. Allicin attenuated depressive-like behaviors of CSDS mice through reducing neuroinflammation, ameliorating iron abnromal accumulation, balacing oxidative stress, and attenuation neuronal apoptosis in the hippocampus via suppression of NLRP3 inflammasome.

Moderators for depressed mood and systemic and transcriptional inflammatory responses: a randomized controlled trial of endotoxin

Activation of the innate immune system is thought to contribute to depression. Multiple social and behavioral factors are also known to instigate depression. Whether these socio-behavioral factors interact with inflammatory stimuli to alter proinflammatory responses and depressed mood is not known. In 115 healthy adults, social, emotional, and behavioral factors were assessed at baseline. A single infusion of endotoxin (Escherichia coli; 0.8 ng/kg of body weight) or placebo (0.9% saline) was administered with hourly assessment of depressed mood and proinflammatory cytokines (interleukin-6 (IL-6); tumor necrosis factor-α (TNF)). Inflammatory gene expression was examined at 30 min after infusion, prior to increase of inflammatory cytokines. As compared to placebo, endotoxin-induced increases of depressed mood were moderated by baseline levels of perceived stress, trait sensitivity to social disconnection, and severity of symptoms of anxiety and depression (all Ps < 0.05) but not early life stress, social status, social support, neuroticism, or sleep disturbance. Anxiety symptoms remained significant in multivariable analyses (P < 0.01). None of these socio-behavioral factors were related to increases in proinflammatory cytokines. Transcriptome profiling analyses indicated that perceived stress, sensitivity to social disconnection, and depressive symptoms were associated with increased activation of pro-inflammatory transcription control pathways (i.e., activator protein-1, nuclear factor-κB) in response to endotoxin (all Ps < 0.05). These results indicate that an array of socio-behavioral factors, which are associated with depression risk, modify vulnerability to inflammation-induced depressed mood. Together, these observations may be used to help target therapeutic interventions to mitigate occurrence of the inflammatory biotype of depression.

Mood Disorders, Accelerated Aging, and Inflammation: Is the Link Hidden in Telomeres?

Mood disorders are associated with an increased risk of aging-related diseases, which greatly contribute to the excess morbidity and mortality observed in affected individuals. Clinical and molecular findings also suggest that mood disorders might be characterized by a permanent state of low-grade inflammation. At the cellular level, aging translates into telomeres shortening. Intriguingly, inflammation and telomere shortening show a bidirectional association: a pro-inflammatory state seems to contribute to aging and telomere dysfunction, and telomere attrition is able to induce low-grade inflammation. Several independent studies have reported shorter telomere length and increased levels of circulating inflammatory cytokines in mood disorders, suggesting a complex interplay between altered inflammatory–immune responses and telomere dynamics in the etiopathogenesis of these disorders. In this review, we critically discuss studies investigating the role of telomere attrition and inflammation in the pathogenesis and course of mood disorders, and in pharmacological treatments with psychotropic medications.

Low-Grade Inflammation as a Predictor of Antidepressant and Anti-Inflammatory Therapy Response in MDD Patients: A Systematic Review of the Literature in Combination With an Analysis of Experimental Data Collected in the EU-MOODINFLAME Consortium

Low-grade inflammation plays a role not only in the pathogenesis of major depressive disorder (MDD) but probably also in the poor responsiveness to regular antidepressants. There are also indications that anti-inflammatory agents improve the outcomes of antidepressants. Aim: To study whether the presence of low-grade inflammation predicts the outcome of antidepressants, anti-inflammatory agents, or combinations thereof. Methods: We carried out a systematic review of the literature on the prediction capability of the serum levels of inflammatory compounds and/or the inflammatory state of circulating leukocytes for the outcome of antidepressant/anti-inflammatory treatment in MDD. We compared outcomes of the review with original data (collected in two limited trials carried out in the EU project MOODINFLAME) on the prediction capability of the inflammatory state of monocytes (as measured by inflammatory gene expression) for the outcome of venlafaxine, imipramine, or sertraline treatment, the latter with and without celecoxib added. Results: Collectively, the literature and original data showed that: 1) raised serum levels of pro-inflammatory compounds (in particular of CRP/IL-6) characterize an inflammatory form of MDD with poor responsiveness to predominately serotonergic agents, but a better responsiveness to antidepressant regimens with a) (add-on) noradrenergic, dopaminergic, or glutamatergic action or b) (add-on) anti-inflammatory agents such as infliximab, minocycline, or eicosapentaenoic acid, showing-next to anti-inflammatory-dopaminergic or lipid corrective action; 2) these successful anti-inflammatory (add-on) agents, when used in patients with low serum levels of CRP/IL-6, decreased response rates in comparison to placebo. Add-on aspirin, in contrast, improved responsiveness in such "non-inflammatory" patients; 3) patients with increased inflammatory gene expression in circulating leukocytes had a poor responsiveness to serotonergic/noradrenergic agents. Conclusions: The presence of inflammation in patients with MDD heralds a poor outcome of first-line antidepressant therapies. Immediate step-ups to dopaminergic or glutamatergic regimens or to (add-on) anti-inflammatory agents are most likely indicated. However, at present, insufficient data exist to design protocols with reliable inflammation parameter cutoff points to guide such therapies, the more since detrimental outcomes are possible of anti-inflammatory agents in "non-inflamed" patients.

Baseline Serum Levels of Beclin-1, but Not Inflammatory Factors, May Predict Antidepressant Treatment Response in Chinese Han Patients With MDD: A Preliminary Study

Currently, the choice of medical treatment for major depressive disorder (MDD) is primarily based on a trial-and-error process. Thus, identification of individual factors capable of predicting treatment response is of great clinical relevance. Recent work points towards beclin-1 and inflammatory factors as potential biomarkers of antidepressant treatment response. The primary aim of the study was to investigate whether pre-treatment serum levels of beclin-1 and inflammatory factors could predict antidepressant treatment response in Chinese Han patients with MDD. Forty patients with MDD were treated with either a selective serotonin reuptake inhibitor (SSRI) (paroxetine in 20 cases) or a serotonin-norepinephrine reuptake inhibitor (SNRI) (duloxetine in 13 cases and venlafaxine in 7 cases). Depression scores and serum levels of beclin-1 were measured at the baseline and after 8 weeks of antidepressant treatment. Serum C-reactive protein (CRP), interleukin (IL)-1B, and IL-6 levels were determined using enzyme-linked immunosorbent assay kits at the baseline. Twenty-seven patients were identified as treatment responders, whereas 13 were identified as non-responders after 8 weeks of antidepressant treatment. Baseline serum beclin-1 levels were significantly higher in non-responders than in responders (p = 0.001), whereas no differences were found in baseline serum CRP, IL-1B, or IL-6 levels between responders and non-responders. There were no significant correlations between baseline levels of beclin-1 and baseline IL-1β, IL-6, and CRP levels-neither in the total sample nor in responder and non-responder groups. Moreover, logistic regression models and a random forest model showed that baseline serum beclin-1, but not inflammatory factors, was an independent and the most important predictor for antidepressant treatment response. Furthermore, serum beclin-1 levels were significantly increased in responders (p = 0.027) but not in non-responders after 8 weeks of treatment (p = 0.221). Baseline serum beclin-1 levels may be a predictive biomarker of antidepressant response in patients with MDD. Moreover, beclin-1 may be involved in the therapeutic effect of antidepressant drugs.